> If we just record the TSC unshifted, in 27 bits, at 4GHz, that gives us
If we use 32 bits instead of 27, then the timestamp events are only
about once per second, which is probably fine for overhead ... ?
I think we're OK losing 5 bits of precision, that's only 32 cycles,
given all the CPU reordering stuff we've talked about here,
not-quite-synced TSCs, etc. I suspect you thought we were
shifting by much more than this, in reality it was 5-10 bits,
with timestamp events inbetween, though we put wall time in
them, which I think was a mistake.
(note: I'm not suggesting we have to use this compact a format,
at least by default)
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